The purpose of this investigation is to examine the relationships between endogenous prostaglandins and bronchial asthma. The study involves development of sensitive, specific radioimmunoassays for a number of prostaglandins which may be of importance in asthma and utilization of these methods for quantitative assay of endogenous prostaglandins in body fluids of normal and asthmatic subjects. The range of values in normal subjects under a variety of circumstances will be established. Thereafter the possible differences in measurements of asthmatic patients will be determined during resting conditions, spontaneous asthma, asthma provocation studies and in relation to treatment with various medications. If differences in prostaglandin measurements of normal and asthmatic subjects are observed, attempts will be made to alter the abnormal responses of asthmatic patients by therapeutic maneuvers.